KUALA LUMPUR - Investigators examining the March 8 disappearance of a Malaysia Airlines plane with 239 people aboard believe it most likely that the plane flew into the southern Indian Ocean, a source close to the investigation said on Wednesday.

"The working assumption is that it went south, and furthermore that it went to the southern end of that corridor," said the source, referring to a search area stretching from west of Indonesia to the Indian Ocean west of Australia.

Australia begins search for missing Malaysian plane	Little progress as plane search spans Asia